Abstract: The A burst and B burst for tracking are recorded with the width of track pitch, the address signal is recorded as the same signal with the interval equal to two track pitches (2×Tp) and B1 bit is also recorded with deviation of one track pitch from the address signal with the interval equal to two track pitches (2×Tp). Therefore, the servo pattern of one track can be written as much as one track pitch and thereby the recording time can be shortened. Moreover, accurate track address can be calculated by the correcting process using the B1 bit.

Abstract: A magnetic recording and reproducing apparatus arranged to use a magnetic tape. The apparatus operates to derive the current taken-up position of the magnetic tape from the signals that are proportional to the rotation frequencies of a capstan motor, a supply reel and a take-up reel. Only when the taken-up position is near the tape end, the apparatus activates LEDs (light emitting elements) for sensing the tape end and photo-transistors (light receiving elements), for sensing the tape end.

Abstract: A method and apparatus for compensating for written-in repeatable runout in a disc drive is provided. Compensation values are determined through an iterative learning process in which parameters of the learning process such as learning gain, servo loop gain, etc. are functions of the iteration number. The learning process also employs a nominal double integrator model of an actuator of the disc storage system. The learning process is also a function of a zero-phase low-pass filter.

Abstract: A signal recording apparatus and method supplies recording signals to at least a pair of positive and negative azimuth magnetic heads provided on a rotary drum so as to be adjacent to each other in all recording occasions for recording by the magnetic heads when a recording track having a first track width is formed on the magnetic tape, while the apparatus and method supplies recording signals to at least the pair of positive and negative azimuth magnetic heads once in a predetermined number of recording occasions for recording by the recording heads when a recording track having a second track width which is larger than the first track width is formed on the magnetic tape.

Abstract: A seek control system in a disk system, in which the object measured is a mechanism including a voice coil motor which positions a head, and in which the temperature of the voice coil motor is detected and seek operations are controlled based on the thus detected temperature, includes a unit for determining the amount of heat causing the temperature rise of the object under measurement as the square of a voice coil motor current command value multiplied by predetermined coefficients; a unit for integrating the result obtained by subtracting the amount of naturally radiated heat from the amount of heat including the amount of heat causing the thus determined temperature rise, to determine the amount of heat in the object; and a unit for detecting the temperature of the object in accordance with the thus determined amount of heat in the object.

Abstract: A finite impulse response (FIR) filter and a Viterbi detector system for a magnetic read channel are disclosed. The FIR equalizer generates equalized sampled outputs to the Viterbi detector system. The Viterbi detector system determines the most probable value of all references, R.sub.i by accumulating a summation of data sample values, D.sub.t, for selected legal bit sequences over a significant amount of random data. The summation and count of data samples are output to a system microprocessor for calculation of an average reference for each path of the Viterbi system. The Viterbi detector system also calculates, in real time, magnitude of differences between the output data received from the FIR equalizer and transition references for each data sample to generate transition metrics, adds transition metrics to state metrics from the source node of two paths, and compares the result. The lesser of the two results yields the most likely correct state metric.

Abstract: In a disk drive using a write-wide inductive write element and a read-narrow magneto-resistive read element within a head transducer assembly for writing and reading magnetic patterns on a rotating magnetic storage disk in a plurality of concentric tracks, a track pattern formed in each concentric track includes embedded servo wedges wherein each wedge includes a servo position portion which is offset from a centerline of both the servo sector and a following user data sector by an amount related to offset between the inductive write and magneto-resistive elements of the head transducer assembly. Furthermore, the servo sector contains four servo bursts. The servo bursts are arranged such that each sequential burst is offset from a previous burst by a fractional offset increment. The fractional offset increment is typically one-third of a track pitch.